24901-29-9

Upstream product

• 29587-76-6 (+)-3r-methyl-1-phenyl-phospholane 1t-oxide 
• 7564-51-4 2,5-dihydro-3-methyl-1-phenyl-1H-phosphole 1-oxide 
• 34868-22-9 3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-phosphole-1-oxide 

Downstream Products

• 538-75-0 dicyclohexyl-carbodiimide 
• 34868-24-1 1-iodomethyl-3-methyl-1-phenyl-phospholanium; iodide 
• 1192586-20-1 1-(2-methoxy-2-oxoethyl)-3-methyl-1-phenylphospholanium bromide 
• 313478-78-3 3-methyl-1-phenylphospholane-borane complex 
• 19713-73-6 methyl (2Z)-3-phenylprop-2-enoate 
• 103-26-4 Methyl cinnamate 

Relevant academic research and scientific papers

Bridged [2.2.1] bicyclic phosphine oxide facilitates catalytic γ-umpolung addition-Wittig olefination

A novel bridged [2.2.1] bicyclic phosphine oxide, devised to circumvent the waste generation and burdens of purification that are typical of reactions driven by the generation of phosphine oxides, has been prepared in three steps from commercially availab

Synthesis of Functionalized Furans via Chemoselective Reduction/Wittig Reaction Using Catalytic Triethylamine and Phosphine

An efficient protocol for the synthesis of highly functionalized furans via intramolecular Wittig reaction has been developed using catalytic amounts of phosphine and triethylamine. Silyl chloride served as the initial promoter to activate the phosphine oxide. Reduction of the activated phosphine oxide by hydrosilane resulted in generation of phosphine, while decomposition of Et3N·HCl resulted in regeneration of base, which mediated formation of phosphorus ylide. Remarkably, the in situ generated byproduct, Et3N·HCl, also catalyzes reduction of phosphine oxide.

Part I: The development of the catalytic wittig reaction

We have developed the first catalytic (in phosphane) Wittig reaction (CWR). The utilization of an organosilane was pivotal for success as it allowed for the chemoselective reduction of a phosphane oxide. Protocol optimization evaluated the phosphane oxide precatalyst structure, loading, organosilane, temperature, solvent, and base. These studies demonstrated that to maintain viable catalytic performance it was necessary to employ cyclic phosphane oxide precatalysts of type 1. Initial substrate studies utilized sodium carbonate as a base, and further experimentation identified N,N-diisopropylethylamine (DIPEA) as a soluble alternative. The use of DIPEA improved the ease of use, broadened the substrate scope, and decreased the precatalyst loading. The optimized protocols were compatible with alkyl, aryl, and heterocyclic (furyl, indolyl, pyridyl, pyrrolyl, and thienyl) aldehydes to produce both di- and trisubstituted olefins in moderate-to-high yields (60-96 %) by using a precatalyst loading of 4-10 mol %. Kinetic E/Z selectivity was generally 66:34; complete E selectivity for disubstituted α,β-unsaturated products was achieved through a phosphane-mediated isomerization event. The CWR was applied to the synthesis of 54, a known precursor to the anti-Alzheimer drug donepezil hydrochloride, on a multigram scale (12.2 g, 74 % yield). In addition, to our knowledge, the described CWR is the only transition-/heavy-metal-free catalytic olefination process, excluding proton-catalyzed elimination reactions. A point of difference: By utilizing an organosilane to chemoselectively reduce a phosphane oxide precatalyst to a phosphane (see scheme), the first catalytic (in phosphane) Wittig reaction has been developed. The methodology has been applied to the synthesis of 22 disubstituted and 24 trisubstituted olefins, including a multigram synthesis of a precursor to the anti-Alzheimer drug donepezil hydrochloride.

In situ phosphine oxide reduction: A catalytic appel reaction

Several important reactions in organic chemistry thrive on stoichiometric formation of phosphine oxides from phosphines. To avoid the resulting burden of waste and purification, cyclic phosphine oxides were evaluated for new catalytic reactions based on in situ regeneration. First, the ease of silane-mediated reduction of a range of cyclic phosphine oxides was explored. In addition, the compatibility of silanes with electrophilic halogen donors was determined for application in a catalytic Appel reaction based on in situ reduction of dibenzophosphole oxide. Under optimized conditions, alcohols were effectively converted to bromides or chlorides, thereby showing the relevance of new catalyst development and paving the way for broader application of organophosphorus catalysis by in situ reduction protocols. Copyright

A new family of platinum(ii) complexes incorporating five-and six-membered cyclic phosphine ligands

New platinum complexes of the type cis-Pt(L)2Cl2 have been synthesized from five-and six-membered cyclic phosphines, which were prepared after deoxygenating a series of phosphine oxides (3-phospholene oxides, phospholane oxides, a 1,

CATALYTIC WITTIG AND MITSUNOBU REACTIONS

A catalytic Wittig method utilizing a phosphine including the steps of providing a phosphine oxide precatalyst and reducing the phosphine oxide precatalyst to produce the phosphine; forming a phosphonium ylide precursor from the phosphine and a reactant; generating a phosphonium ylide from the phosphonium ylide precursor; reacting the phosphonium yiide precursor with the aldehyde, ketone, or ester to form the olefin and the phosphine oxide which then reenters the cycle. The invention is also directed to a Mitsunobu reaction catalytic in phosphine.